As a default, docker will create 2 files in /var/lib/docker/devicemapper/devicemapper/
-rw——- 1 root root 100G May 25 13:43 /var/lib/docker/devicemapper/devicemapper/data
-rw——- 1 root root 2.0G May 25 13:43 /var/lib/docker/devicemapper/devicemapper/metadata
-rw——- 1 root root 2.0G May 25 13:43 /var/lib/docker/devicemapper/devicemapper/metadata
If the total size of docker meet the 100G limitation, all docker will become read-only.
To fix this, we need to increase the size of data file:
1. Stop docker.
2. Remove data and metadata under /var/lib/docker/devicemapper/devicemapper/
3. Modify /etc/sysconfig/docker, add argument in the files:
other_args=”–storage-opt dm.basesize=50G –storage-opt dm.loopdatasize=1024G –storage-opt dm.loopmetadatasize=20G”
4. Start docker.